387 research outputs found
Enhancing Short-Term Berry Yield Prediction for Small Growers Using a Novel Hybrid Machine Learning Model
This study presents a novel hybrid model that combines two different algorithms to increase
the accuracy of short-term berry yield prediction using only previous yield data. The model integrates both autoregressive integrated moving average (ARIMA) with Kalman filter refinement and neural network techniques, specifically support vector regression (SVR), and nonlinear autoregressive (NAR) neural networks, to improve prediction accuracy by correcting the errors generated by the system. In order to enhance the prediction performance of the ARIMA model, an innovative method is introduced that reduces randomness and incorporates only observed variables and system errors into the state-space system. The results indicate that the proposed hybrid models exhibit greater accuracy in predicting weekly production, with a goodness-of-fit value above 0.95 and lower root mean square error (RMSE) and mean absolute error (MAE) values compared with non-hybrid models. The study highlights several implications, including the potential for small growers to use digital strategies that offer crop forecasts to increase sales and promote loyalty in relationships with large food retail chains. Additionally, accurate yield forecasting can help berry growers plan their production schedules and optimize resource use, leading to increased efficiency and profitability. The proposed model may serve as a valuable information source for European food retailers, enabling growers to form strategic alliances with their customers
La Acción Católica en Cuenca: de las asociaciones obreras a la “ciudadanía moral” en el primer tercio del siglo XX (Estudios)
The development of a sense of citizenry in the province of Azuay, in Ecuador, during the first third of the twentieth century, was linked to the Catholic Action, a lay movement sponsored by the Church aimed at regaining the ground that traditional conservative society believed could be lost to the social and political changes of emerging modernity. During this period, Cuenca was being impacted by economic, social, urban, and cultural transformations, among which the most noteworthy were the opening up of trade with Europe and the resulting flow of ideas. The Catholic Action steered organized labor toward its own ideology, countering liberal concepts and the growing presence of socialist ideology. These lay persons promoted a “moral Christian citizenry” that laid the foundations for a predominantly conservative society.El desarrollo de la ciudadanía en Azuay, Ecuador, durante el primer tercio del siglo XX, estuvo relacionado con la Acción Católica, movimiento seglar tutelado por la Iglesia que pretendía recuperar los espacios que la sociedad tradicional y conservadora creía que podían perderse ante los cambios sociales y políticos de la emergente modernidad. Durante este período, Cuenca se vio afectada por transformaciones económicas, sociales, urbanísticas y culturales, siendo notable la apertura comercial hacia Europa y la consecuente circulación de ideas. La Acción Católica encaminó la organización obrera en función de su propio ideario, en contraposición a los conceptos liberales y a la presencia creciente de la ideología socialista. Los seglares impulsaron una “ciudadanía moral” cristiana que definió las bases de una sociedad predominantemente conservadora
Entrepreneurial intention and university: A necessary relationship in regions with high levels of unemployment
Purpose: Although university entrepreneurship education as a predictor of entrepreneurial intention (EI) has been verified in the academic literature, few studies have analysed its influence in regions with low entrepreneurial activity. This research provides a new point of view by contrasting students' perceptions with what entrepreneurs consider most relevant. We propose an integrative and multiperspective framework based on expectancy theory and the theory of planned behaviour, which includes the moderating effect of gender and family imprinting. Design/methodology: A valid sample of 108 business students from the University of Huelva (Spain) served as the basis of the study, whose data were analysed using consistent partial least squares (PLSc) to validate the scales and subsequently test the hypotheses. In addition, 54 valid questionnaires from local entrepreneurs were used for the comparative analysis between entrepreneurs and students. Findings: Our findings showed that the elements associated with university support have a significant, albeit negative, impact on students' intentions to become entrepreneurs. In terms of moderating variables, no significant differences were found by gender, but significant differences were found in the group with entrepreneurial parents. In relation to the determinants of entrepreneurial success, it was found that the students' conceptions of entrepreneurship were closer to those of the entrepreneurs in Huelva than to those of the successful entrepreneurs. Originality/value: This paper contributes to the academic debate on whether universities in general, and business schools in particular, should promote entrepreneurship as the core of education. We believe that these results, despite the specific and limited scope of the study, may be of great interest for university staff in regions with high levels of structural unemployment and low rates of total early-stage entrepreneurial activity (TEA) to incorporate into their academic programme
Biomasa aérea y contenido de carbono en el campus de la Pontificia Universidad Javeriana de Bogotá
La producción de biomasa y la captura de carbono son elementos de gran importancia a considerar para establecer el estado de los ecosistemas naturales y urbanos. En el presente trabajo se realizó la estimación de la biomasa arbórea, de la producción primaria aérea y la estimación del contenido de carbono del campus de la Pontificia Universidad Javeriana de Bogotá, a partir de la cuantificación de la cobertura arbórea, el cálculo de la biomasa arbórea aérea, la estimación de la producción primaria de biomasa y la estimación del contenido de carbono del campus. Los resultados muestran que la cobertura arbórea cuantificada fue de 21.16 ha. La biomasa aérea arbórea calculada fue para el área 1 de muestreo de 129,05 T/ha, para el área 2 fue de 32,55 T/ha y para el área 3 fue de 90,14 T/ha. La producción primaria de biomasa estimada fue de 626,16 Kg/ha y el contenido de carbono estimado fue de 125,87 T/ha. La producción estimada de biomasa en el campus es comparable a la registrada en los bosques de pino de España, indicando que son áreas de bosques urbanos maduros, con un número considerable de especies introducidas europeas.Biomass production and carbon sequestration are very important elements to be considered in establishing the state of the natural and urban ecosystems. In this paper, the estimation of tree biomass, aboveground primary production and the estimated carbon content of the campus of the Pontificia Universidad Javeriana in Bogota, from the quantification of tree cover, the calculation of biomass aerial tree, estimating the primary production of biomass and carbon estimation campus. The results show that the coverage tree was quantified 21.16 ha. The tree biomass was calculated for the sampling area 1 was 129.05 t / ha, for Area 2 was 32.55 t / ha and for area 3 was 90.14 t / ha. Primary production was estimated biomass of 626.16 kg / ha and the estimated carbon content was 125.87 t / ha. The estimated production of biomass on campus is comparable to that recorded in the pine forests of Spain, indicating that urban forests are areas ripe with a number of European introduced species.Ecólogo (a)Pregrad
Analysis of factors for the transition to a circular economy.
The aim of this thesis is to identify the different factors that influence the transition to a circular economy (CE) leaving behind the conception of a linear economy. Understanding the word ‘factor’ as drivers or barriers for its transition. To identify these factors, the project has followed a determined methodology. Firstly, a literature review has been carried out, by doing so, the most relevant factors in the last two years have been selected. Secondly, semi-structured interviews have been conducted, and as such, valuable information was collected, and in addition, the information gathered in the first step was corroborated with the respondents.
In other words, the project has been approached from an academic and practical perspective in order to gather the most real information
Análisis de los Tweets de los minoristas de alimentación que operan en España y UK. Cómo el análisis del contenido generado por los usuarios en Twitter puede ayudar a las cooperativas agroalimentarias a establecer mejores relaciones con sus clientes
Twitter is an outstanding social media platform that food firms are using to share information with consumers. This research aims to determine the behavior of different food retailers in Spain and the UK in relation to Twitter to shed light on their interests and similarities. This study collected and analyzed a total of 54,000 tweets from 17 food retailers from the social media platform Twitter. Analyzing food retailers’ generated content on Twitter by wordcount, content analysis and social network analysis, several characteristics were detected that could be relevant for suppliers of these food retailers. The output reveals differences among food retailers as well as groups with different strategies within each market and confirms the potential of Twitter data as an information source for conducting marketing studies. Similarly, we found that the adoption of Twitter data analytics by marketing managers of agrifood cooperatives could be very useful for advancing customer-centric strategies. Finally, this research presents its limitations and proposes new lines of future work.Twitter es una destacada plataforma de medios sociales utilizada ampliamente por las empresas alimentarias para compartir información con los consumidores. Este estudio tiene como objetivo determinar el comportamiento en Twitter de diferentes minoristas de alimentación que operan en España y el Reino Unido para arrojar luz sobre sus intereses y afinidades. El estudio recopiló y analizó un total de 54.000 tweets de las cuentas oficiales de Twitter de 17 minoristas de alimentación. Analizando el contenido generado por los minoristas de alimentación en Twitter con el recuento de palabras, el análisis de contenido generado por estos usuarios y el análisis de redes sociales, se detectaron algunas características que podrían ser relevantes para los proveedores de estos minoristas de alimentación. La identificación de las diferencias en la actividad y las comunicaciones en Twitter, así como también las afinidades entre algunos de ellos, confirman el potencial de los datos de Twitter como fuente de información para realizar estudios de marketing en general. Del mismo modo, descubrimos que la adopción de la analítica de datos de Twitter por los responsables de marketing de las cooperativas agroalimentarias podría ser muy útil para avanzar en las estrategias centradas en el cliente. Finalmente, la investigación presenta las limitaciones y propone nuevas líneas de trabajo futuro.Escuela de Estudios CooperativosFac. de Ciencias Económicas y EmpresarialesTRUEpu
The role of the environment in the formation of women university students’ entrepreneurial intention. the case of Morocco
A pesar de la rápida expansión de la investigación
sobre el espíritu empresarial de
las mujeres, todavía escasean los estudios
que exploren la intersección o simultaneidad
entre género y país en desarrollo. El ambiente
empresarial es fundamental para el emprendimiento
estudiantil. Investigaciones anteriores
han intentado comprender el papel
del entorno empresarial en la formación de la
intención emprendedora de las estudiantes
(WEI), aunque de manera aislada. Este estudio
combina un marco multinivel, planteando
hipótesis con dos dimensiones del entorno
macrosocial, el apoyo universitario percibido
y el apoyo institucional percibido. Además,
se incluyen en el modelo la red social percibida
y las normas subjetivas como constructos
relevantes del entorno microsocial que
pueden afectar a la intención emprender.Despite the rapid expansion of women’s
entrepreneurship research there is a dearth of
studies exploring the intersection or simultaneity
of gender and developing country within
the entrepreneurship field. Entrepreneurial
environment is central to student entrepreneurship.
Previous research has attempted
to understand the role of entrepreneurship
environment in the formation of Women students’
Entrepreneurial Intention (WEI), albeit
in an isolated manner. This study combines a
multi-level framework. We have hypothesized
two dimensions of macrosocial environment,
that is, perceived university support, and perceived
institutional support. In addition, perceived
social network and subjective norms
as the fundamental elements of the microsocial
environment affecting the intention to
start a business
Predicting Time Series Using an Automatic New Algorithm of the Kalman Filter
Time series forecasting is one of the main venues followed by researchers in all areas. For this reason, we develop a new Kalman filter approach, which we call the alternative Kalman filter.
The search conditions associated with the standard deviation of the time series determined by the
alternative Kalman filter were suggested as a generalization that is supposed to improve the classical Kalman filter. We studied three different time series and found that in all three cases, the alternative Kalman filter is more accurate than the classical Kalman filter. The algorithm could be generalized to time series of a different length and nature. Therefore, the developed approach can be used to predict any time series of data with large variance in the model error that causes convergence problems in the prediction
Deterministic Chaos Detection and Simplicial Local Predictions Applied to Strawberry Production Time Series
In this work, we attempted to find a non-linear dependency in the time series of strawberry
production in Huelva (Spain) using a procedure based on metric tests measuring chaos. This study
aims to develop a novel method for yield prediction. To do this, we study the system’s sensitivity
to initial conditions (exponential growth of the errors) using the maximal Lyapunov exponent. To
check the soundness of its computation on non-stationary and not excessively long time series, we
employed the method of over-embedding, apart from repeating the computation with parts of the
transformed time series. We determine the existence of deterministic chaos, and we conclude that
non-linear techniques from chaos theory are better suited to describe the data than linear techniques
such as the ARIMA (autoregressive integrated moving average) or SARIMA (seasonal autoregressive
moving average) models. We proceed to predict short-term strawberry production using Lorenz’s
Analog MethodThis research was funded by Junta de Andalucía. Consejería de la Presidencia, Administración
Pública e Interior. Secretaría General de Acción Exterior grant number G/82A/44103/00 0
Successful rehabilitation approach for sustainable regain in cocoa production systems in South-East Asia
In Malaysia an intensively managed high input full sun cacao (Theobroma cacao L.) plantation can reach high yields of 1.5 to 2 t dry beans per ha. Following a high production period of 10 years the yields often decrease markedly. Focusing on leading depleted cacao plantations sustainably back to full production a research project was initiated in June 2011 using a diversification approach with agroforestry systems. The experimental site is located on a large commercial farm in the humid tropical lowlands of peninsular Malaysia, in the region of Kuala Lipis. In a field trial with a strip-split-plot design, three different production systems are compared under two tree age conditions: newly planted and old rehabilitated cacao trees, after the removal of the original canopy back to the leader structure. The examined production systems are: i) high external inputs in a mono crop full sun system representing the common practice of large cacao plantations in South-East Asia (COM); ii) medium level of external inputs in an agroforestry system of low diversity focusing on leguminous and timber trees (AF LD); iii) low external inputs in an agroforestry system of high diversity and high density shade trees including annual crops and fruit trees (AF HD). The existing twenty-two-year-old plantation with the original canopy and a high input level serves as control treatment (REF).
When cocoa yields decline after the initial high production period trees are often replanted. This results in a non-productive phase lasting several years before the young trees start to develop pods and even longer before yields reach a remunerative level. Rehabilitating old low producing trees on the other hand, as practiced in the present experiment, is expected to re-establish higher yields more quickly than re-planting.
The first full harvest in the trial started in September 2012, 15 months after the rehabilitation pruning. Between October 2012 and June 2013 (main harvest) an average of 471.2 kg dry beans per ha were harvested in the control treatment. The yields of the common practice treatments already amounted to 41.6 % of the control. This is a very promising result, especially in view of the development of young trees which will take at least another year before the first pod development. Yields in the agroforestry systems increased less quickly as tree development under shade and with lower fertilizer input is inherently slower
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